Oral care compositions and methods of use

ABSTRACT

Described herein are oral care compositions comprising a basic amino acid; a combination of zinc ion sources; and from about 0.75 wt. % to about 2 wt. % of a chelating system; along with methods of making and using same.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from PCT/CN2016/086994, filed Jun. 24, 2016, the contents of which are hereby incorporated by reference in their entirety.

BACKGROUND

The viscosity profile of most toothpastes either stabilize at the time of production or show an increase in viscosity over time and/or stabilize within the product's shelf-life. However, certain arginine-based oral care compositions comprising cationic metal ions, e.g. zinc, exhibit a drop in viscosity and then stabilize within four to eight weeks after production. Maintaining the formula viscosity within a certain range is critical because viscosity impacts physical stability as well as processability.

As such, there remains a need to reconcile physical stability with processability. Certain embodiments of the present invention are designed to address this, and other, needs.

BRIEF SUMMARY

Some embodiments of the present invention provide oral care compositions comprising a basic amino acid in free or salt wherein the amino acid is selected from arginine, lysine, and a combination thereof, a combination of zinc ion sources; and a from about 1 wt. % to about 2 wt. % of a chelating system. In some embodiments, the chelating system comprises tetrasodium pyrophosphate.

In some embodiments, the oral care compositions of the present invention demonstrate the ability to avoid viscosity loss over an extended period of time, e.g. after 13 weeks.

In one aspect the invention is an oral care composition (Composition 1.0) comprising:

-   -   a. A basic amino acid in free or salt from, wherein the amino         acid is selected from arginine, lysine, and combinations         thereof; (e.g., free form arginine);     -   b. zinc oxide and zinc citrate;     -   c. a fluoride source (e.g., sodium fluoride); and     -   d. a silica abrasive which exhibits an acid pH when measured as         an aqueous slurry (e.g., prophy silica).

For example, the invention contemplates any of the following compositions (unless otherwise indicated, values are given as percentage of the overall weight of the composition):

-   1.01 Composition 1.0 wherein the silica abrasive which exhibits an     acid pH when measured as an aqueous slurry is prophy silica. -   1.02 Any of the preceding compositions wherein the silica abrasive     which exhibits an acid pH when measured as an aqueous slurry is     Sylodent 783. -   1.03 Any of the preceding compositions wherein the silica abrasive     exhibits a pH of 3.5-4.5 in an aqueous slurry of the abrasive. -   1.04 Any of the preceding compositions wherein the silica abrasive     which exhibits an acid pH when measured as an aqueous slurry is     present in an amount from 2 to 35 weight percent. -   1.05 Any of the preceding compositions wherein the silica abrasive     which exhibits an acid pH when measured as an aqueous slurry is     present in an amount from 3 to 15 weight percent. -   1.06 Any of the preceding compositions wherein the silica abrasive     which exhibits an acid pH when measured as an aqueous slurry is     present in an amount selected from 2 wt. %, 3 wt. %, 4% wt. %, 5 wt.     %, 6 wt. %, 7 wt. %, 8 wt. %, 9 wt. %, 10 wt. %, 11 wt. %, 12 wt. %,     13 wt. %, 14 wt. %, 15 wt. %, 16 wt. %, 17 wt. %, 18 wt. %, 19 wt.     %, 20 wt. %. -   1.07 Any of the preceding compositions wherein the basic amino acid     has the L-configuration (e.g., L-arginine). -   1.08 Any of the preceding compositions wherein the basic amino acid     is arginine or lysine is in free form. -   1.09 Any of the preceding compositions wherein the basic amino acid     is provided in the form of a di- or tri-peptide comprising arginine     or lysine, or salts thereof. -   1.10 Any of the preceding compositions wherein the basic amino acid     is arginine or lysine, and wherein the arginine or lysine is present     in an amount corresponding to 1% to 15%, e.g., 3 wt. % to 10 wt. %     of the total composition weight, about e.g., 1.5%, 4%, 5%, or 8%,     wherein the weight of the basic amino acid is calculated as free     form. -   1.11 Any of the preceding compositions wherein the amino acid is     arginine from 0.1 wt. %-6.0 wt. %. (e.g., about 1.5 wt %). -   1.12 Any of the preceding compositions wherein the amino acid is     arginine from about 1.5 wt. %. -   1.13 Any of the preceding compositions wherein the amino acid is     arginine from 4.5 wt. %-8.5 wt. % (e.g., 5.0%). -   1.14 Any of the preceding compositions wherein the amino acid is     arginine from about 5.0 wt. %. -   1.15 Any of the preceding compositions wherein the amino acid is     arginine from 3.5 wt. %-9 wt. %. -   1.16 Any of the preceding compositions wherein the amino acid is     arginine from about 8.0 wt. %. -   1.17 Any of the preceding compositions wherein the amino acid is     L-arginine. -   1.18 Any of the preceding compositions wherein the amino acid is a     free form arginine. -   1.19 Any of the preceding compositions wherein the basic amino acid     is lysine (e.g., 2% wt., 3% wt., 4% wt., 5% wt., 6% wt.), (e.g., 4%     wt.). -   1.20 Any of the preceding compositions wherein the amino acid is     lysine from 1.0 wt. %-6.0 wt. %. -   1.21 Any of the preceding compositions wherein the amino acid is     lysine from about 1.5 wt. %. -   1.22 Any of the preceding compositions wherein the amino acid is     lysine from about 4.0 wt. %. -   1.23 Any of the preceding compositions wherein the amino acid is     L-lysine. -   1.24 Any of the preceding compositions wherein the amino acid is     free form lysine. -   1.25 Any of the preceding compositions wherein the amino acid is     arginine or lysine in partially or wholly in salt form. -   1.26 Composition 1.25 wherein the amino acid is arginine phosphate. -   1.27 Composition 1.25 wherein the amino acid is arginine     hydrochloride. -   1.28 Composition 1.25 wherein the amino acid is arginine     bicarbonate. -   1.29 Composition 1.25 wherein the amino acid is lysine phosphate. -   1.30 Composition 1.25 wherein the amino acid is lysine     hydrochloride. -   1.31 Composition 1.25 wherein the amino acid is lysine bicarbonate. -   1.32 Any of the preceding compositions wherein the amino acid is     arginine or lysine ionized by neutralization with an acid or a salt     of an acid. -   1.33 Any of preceding compositions wherein the composition is     ethanol-free. -   1.34 Any of the preceding compositions further comprising a fluoride     source selected from: stannous fluoride, sodium fluoride, potassium     fluoride, sodium monofluorophosphate, sodium fluorosilicate,     ammonium fluorosilicate, amine fluoride (e.g.,     N′-octadecyltrimethylendiamine-N,N,N′-tris(2-ethanol)-dihydrofluoride),     ammonium fluoride, titanium fluoride, hexafluorosulfate, and     combinations thereof. -   1.35 The composition of 1.34, wherein the fluoride source is     stannous fluoride. -   1.36 Any of the preceding compositions wherein the fluoride source     is a fluorophosphate. -   1.37 Any of the preceding compositions wherein the fluoride source     is sodium monofluorophosphate. -   1.38 The composition of 1.34, wherein the fluoride source is sodium     fluoride. -   1.39 Any of the preceding compositions wherein the fluoride source     is a fluoride salt present in an amount of 0.1 wt. % to 2 wt. % (0.1     wt %-0.6 wt. %) of the total composition weight (e.g., sodium     fluoride (e.g., about 0.32 wt. %) or sodium monofluorophosphate). -   1.40 Any of the preceding compositions wherein the fluoride source     is sodium fluoride in an amount about 0.32 wt. % based on the weight     of the composition. -   1.41 Any of the preceding compositions wherein the fluoride source     is a soluble fluoride salt which provides fluoride ion in an amount     of from 50 to 25,000 ppm (e.g., 750-2000 ppm, e.g., 1000-1500 ppm,     e.g., about 1000 ppm, e.g., about 1450 ppm) -   1.42 Any of the preceding compositions wherein the fluoride source     is sodium fluoride which provides fluoride in an amount from     750-2000 ppm (e.g., about 1450 ppm). -   1.43 Any of the preceding compositions wherein the fluoride source     is selected from sodium fluoride and sodium monofluorophosphate and     which provides fluoride in an amount from 1000 ppm-1500 ppm. -   1.44 Any of the preceding compositions wherein the fluoride source     is sodium fluoride or sodium monofluorophosphate and which provides     fluoride in an amount of about 1450 ppm. -   1.45 Any of the preceding compositions wherein the pH is between 6.0     and 10.5, e.g., 7.0 to 9.0, e.g., about 8.0. -   1.46 Any of the preceding compositions further comprising calcium     carbonate. -   1.47 The composition of 1.46, wherein the calcium carbonate is a     precipitated calcium carbonate high absorption (e.g., 20% to 30% by     weight of the composition) (e.g., 25% precipitated calcium carbonate     high absorption). -   1.48 The composition of 1.47, further comprising a precipitated     calcium carbonate—light (e.g., about 10% precipitated calcium     carbonate—light) (e.g., about 10% natural calcium carbonate). -   1.49 Any of the preceding compositions further comprising an     effective amount of one or more alkali phosphate salts, e.g.,     sodium, potassium or calcium salts, e.g., selected from alkali     dibasic phosphate and alkali pyrophosphate salts, e.g., alkali     phosphate salts selected from sodium phosphate dibasic, potassium     phosphate dibasic, dicalcium phosphate dihydrate, calcium     pyrophosphate, tetrasodium pyrophosphate, tetrapotassium     pyrophosphate, sodium tripolyphosphate, disodium     hydrogenorthophoshpate, monosodium phosphate, pentapotassium     triphosphate and mixtures of any of two or more of these, in an     amount of 0.1-20%, e.g., 0.1-8%, e.g., e.g., 0.2 to 5%, e.g., 0.3 to     2%, e.g., 0.3 to 1%, e.g about 0.5%, about 1%, about 2%, about 5%,     about 6%, by weight of the composition. -   1.50 Any of the preceding compositions comprising tetrapotassium     pyrophosphate, disodium hydrogenorthophosphate, monosodium     phosphate, and pentapotassium triphosphate. -   1.51 Any of the preceding compositions, wherein the composition     further comprises stannous pyrophosphate, wherein the stannous     pyrophosphate is from 0.1%-3% by wt. of the composition. (e.g.,     about 1% by wt. of the composition). -   1.52 Any of the preceding compositions comprising a polyphosphate. -   1.53 The composition of 1.49, wherein the polyphosphate is     tetrasodium pyrophosphate. -   1.54 The composition of 1.53, wherein the tetrasodium pyrophosphate     is from 0.1-1.0 wt % (e.g., about 0.5 wt %). -   1.55 Any of the preceding compositions further comprising a second     abrasive or particulate (e.g., silica). -   1.56 Any of the preceding compositions wherein the second abrasive     silica is synthetic amorphous silica. (e.g., 10%-28% by wt.) (e.g.,     8%-25% by wt.) -   1.57 Any of the preceding composition wherein the silica abrasives     are silica gels or precipitated amorphous silicas, e.g. silicas     having an average particle size ranging from 2.5 microns to 12     microns. -   1.58 Any of the preceding compositions further comprising a small     particle silica having a median particle size (d50) of 1-5 microns     (e.g., 3-4 microns) (e.g., about 5 wt. % Sorbosil AC43 from PQ     Chemicals. Warrington, United Kingdom). -   1.59 Any of the preceding compositions wherein 20-30 wt % of the     total silica in the composition is small particle silica (e.g.,     having a median particle size (d50) of 3-4 microns) and wherein the     small particle silica is about 5 wt. % of the oral care composition. -   1.60 Any of the preceding compositions comprising silica wherein the     silica is used as a thickening agent, e.g., particle silica. -   1.61 Any of the preceding compositions further comprising a nonionic     surfactant, wherein the nonionic surfactant is in an amount of from     0.5-5%, e.g, 1-2%, selected from poloxamers (e.g., poloxamer 407),     polysorbates (e.g., polysorbate 20), polyoxyl hydrogenated castor     oil (e.g., polyoxyl 40 hydrogenated castor oil), and mixtures     thereof. -   1.62 Any of the preceding compositions, wherein the poloxamer     nonionic surfactant has an average polyoxypropylene molecular mass     (Mw) of from 3000 to 5000 g/mol and a polyoxyethylene content of     from 60 to 80 mol %, e.g., the poloxamer nonionic surfactant     comprises poloxamer 407. -   1.63 Any of the preceding compositions further comprising glycerin,     wherein the glycerin is in a total amount of 25-40% (e.g., about     35%). -   1.64 The composition of 1.63, wherein the glycerin is in an amount     of about 35% by wt. of the composition. -   1.65 The composition of 1.63, wherein the glycerin is in an amount     of about 26% by wt. of the composition. -   1.66 Any of the preceding compositions further comprising sorbitol,     wherein the sorbitol is in a total amount of 10-40% (e.g., about     23%). -   1.67 The composition of 1.66, wherein the sorbitol is in an amount     of about 13% by wt. of the composition. -   1.68 The composition of any of 1.63-1.67, wherein the glycerin is an     amount of about 26% by wt., and the sorbitol is in an amount of     about 13% by wt. -   1.69 Any of the preceding compositions, wherein the ratio of the     amount of zinc oxide (e.g., wt. %) to zinc citrate (e.g., wt %) is     from 1.5:1 to 4.5:1 (e.g., 2:1, 2.5:1, 3:1, 3.5:1, or 4:1). -   1.70 Any of the preceding compositions, wherein the zinc citrate is     in an amount of from 0.25 to 1.0 wt % (e.g., 0.5 wt. %) and zinc     oxide may be present in an amount of from 0.75 to 1.25 wt % (e.g.,     1.0 wt. %) based on the weight of the oral care composition. -   1.71 Any of the preceding compositions wherein the zinc citrate is     about 0.5 wt %. -   1.72 Any of the preceding compositions wherein the zinc oxide is     about 1.0 wt %. -   1.73 Any of the preceding compositions where the zinc citrate is     about 0.5 wt % and the zinc oxide is about 1.0 wt/o. -   1.74 Any of the preceding compositions further comprising an     additional ingredient selected from: benzyl alcohol,     Methylisothizolinone (“MIT”), Sodium bicarbonate, sodium methyl     cocoyl taurate (tauranol), lauryl alcohol, and polyphosphate. -   1.75 Any of the preceding compositions wherein the benzyl alcohol is     present from 0.1-0.6 wt %., (e.g., 0.1-0.4 wt %) e.g. about 0.1 wt.     %, about 0.2 wt. %, or about 0.3 wt. %. -   1.76 Any of the preceding compositions wherein the benzyl alcohol is     about 0.1 wt %. -   1.77 Any of the preceding compositions wherein the benzyl alcohol is     considered a preservative. -   1.78 Any of the preceding compositions comprising polymer films. -   1.79 Any of the preceding compositions comprising flavoring,     fragrance and/or coloring. -   1.80 The composition of 1.65, wherein the flavoring agent is sodium     saccharin, sucralose, or a mixture thereof. -   1.81 Any of the preceding compositions, wherein the composition     comprises a thickening agents selected from the group consisting of     carboxyvinyl polymers, xanthan gum, carrageenan, hydroxyethyl     cellulose and water soluble salts of cellulose ethers (e.g., sodium     carboxymethyl cellulose and sodium carboxymethyl hydroxyethyl     cellulose). -   1.82 Any of the preceding compositions, wherein the compositions     comprises sodium carboxymethyl cellulose (e.g., from 0.5 wt. %-1.5     wt. %). -   1.83 Any of the preceding compositions comprising from 5%-40%, e.g.,     10%-35%, e.g., about 15%, 25%, 30%, and 35% water. -   1.84 Any of the preceding compositions comprising an additional     antibacterial agent selected from halogenated diphenyl ether (e.g.     triclosan), herbal extracts and essential oils (e.g., rosemary     extract, tea extract, magnolia extract, thymol, menthol, eucalyptol,     geraniol, carvacrol, citral, honokiol, catechol, methyl salicylate,     epigallocatechin gallate, epigallocatechin, gallic acid, miswak     extract, sea-buckthorn extract), bisguanide antiseptics (e.g.,     chlorhexidine, alexidine or octenidine), quaternary ammonium     compounds (e.g., cetylpyridinium chloride (CPC), benzalkonium     chloride, tetradecylpyridinium chloride (TPC),     N-tetradecyl-4-ethylpyridinium chloride (TDEPC)), phenolic     antiseptics, hexetidine, octenidine, sanguinarine, povidone iodine,     delmopinol, salifluor, metal ions (e.g., zinc salts and zinc     compounds, for example, Zinc Chloride, Zinc Lactate, Zinc Sulfate,     Zinc Oxide, stannous salts, copper salts, iron salts), sanguinarine,     propolis and oxygenating agents (e.g., hydrogen peroxide, buffered     sodium peroxyborate or peroxycarbonate), phthalic acid and its     salts, monoperthalic acid and its salts and esters, ascorbyl     stearate, oleoyl sarcosine, alkyl sulfate, dioctyl sulfosuccinate,     salicylanilide, domiphen bromide, delmopinol, octapinol and other     piperidino derivatives, nicin preparations, chlorite salts; and     mixtures of any of the foregoing. -   1.85 Any of the preceding compositions comprising an antioxidant,     e.g., selected from the group consisting of Co-enzyme Q10, PQQ,     Vitamin C, Vitamin E, Vitamin A, BHT, anethole-dithiothione, and     mixtures thereof. -   1.86 Any of the preceding compositions comprising a whitening agent. -   1.87 Any of the preceding compositions comprising a whitening agent     selected from a whitening active selected from the group consisting     of peroxides, metal chlorites, perborates, percarbonates,     peroxyacids, hypochlorites, and combinations thereof. -   1.88 Any of the preceding compositions further comprising hydrogen     peroxide or a hydrogen peroxide source, e.g., urea peroxide or a     peroxide salt or complex (e.g., such as peroxyphosphate,     peroxycarbonate, perborate, peroxysilicate, or persulphate salts;     for example calcium peroxyphosphate, sodium perborate, sodium     carbonate peroxide, sodium peroxyphosphate, and potassium     persulfate), or hydrogen peroxide polymer complexes such as hydrogen     peroxide-polyvinyl pyrrolidone polymer complexes. -   1.89 Any of the preceding compositions further comprising an agent     that interferes with or prevents bacterial attachment, e.g., ethyl     lauryl arginate (ELA) or chitosan. -   1.90 Any of the preceding compositions comprising:     -   a. about 1.0% zinc oxide     -   b. about 0.5% zinc citrate     -   c. about 1.5% L-arginine     -   d. about 0.32% sodium fluoride,     -   e. about 3 wt. % to 15 wt. % silica abrasive which exhibits an         acid pH when measured as an aqueous slurry (e.g., prophy silica)         (e.g., Sylodent 783) -   1.91 Any of the preceding compositions comprising:     -   a. about 1.0% zinc oxide     -   b. about 0.5% zinc citrate     -   c. about 5° % L-arginine     -   d. about 0.32% sodium fluoride     -   e. about 10 wt./o to 15 wt. % silica abrasive which exhibits an         acid pH when measured as an aqueous slurry (e.g., prophy silica)         (e.g., Sylodent 783), and -   1.92 Any of the preceding compositions comprising:     -   a. about 1.0% zinc oxide     -   b. about 0.5% zinc citrate     -   c. about 5° % L-arginine     -   d. about 0.32% sodium fluoride;     -   e. about 3 wt. % to 15 wt. % silica abrasive which exhibits an         acid pH when measured as an aqueous slurry. (e.g., prophy         silica) (e.g., Sylodent 783) -   1.93 Any of the preceding compositions comprising a silica, wherein     the silica is Zeodent 114. -   1.94 Any of the preceding compositions effective upon application to     the oral cavity, e.g., by rinsing, optionally in conjunction with     brushing, to (i) reduce or inhibit formation of dental caries. (ii)     reduce, repair or inhibit pre-carious lesions of the enamel, e.g.,     as detected by quantitative light-induced fluorescence (QLF) or     electrical caries measurement (ECM), (iii) reduce or inhibit     demineralization and promote remineralization of the teeth, (iv)     reduce hypersensitivity of the teeth, (v) reduce or inhibit     gingivitis, (vi) promote healing of sores or cuts in the     mouth, (vii) reduce levels of acid producing bacteria, (viii) to     increase relative levels of arginolytic bacteria, (ix) inhibit     microbial biofilm formation in the oral cavity, (x) raise and/or     maintain plaque pH at levels of at least pH 5.5 following sugar     challenge, (xi) reduce plaque accumulation, (xii) treat, relieve or     reduce dry mouth, (xiii) clean the teeth and oral cavity (xiv)     reduce erosion, (xv) prevents stains and/or whiten teeth, (xvi)     immunize the teeth against cariogenic bacteria; and/or (xvii)     promote systemic health, including cardiovascular health, e.g., by     reducing potential for systemic infection via the oral tissues. -   1.95 Any of the preceding oral compositions, wherein the oral     composition may be any of the following oral compositions selected     from the group consisting of: a toothpaste or a dentifrice, a     mouthwash or a mouth rinse, a topical oral gel, and a denture     cleanser. -   1.96 A composition obtained or obtainable by combining the     ingredients as set forth in any of the preceding compositions. -   1.97 A composition obtained or obtainable by combining the     ingredients as set forth in any of the preceding compositions. -   1.98 A composition for use as set for in any of the preceding     compositions.

In another embodiment, the invention encompasses a method to improve oral health comprising applying an effective amount of the oral composition of any of the embodiments set forth above (e.g., any of Composition 1.0 et seq) to the oral cavity of a subject in need thereof, e.g.,

-   -   i. a method to reduce or inhibit formation of dental caries,         reduce, repair or inhibit early enamel lesions, e.g., as         detected by quantitative light-induced fluorescence (QLF) or         electrical caries measurement (ECM),     -   ii. reduce or inhibit demineralization and promote         remineralization of the teeth,     -   iii. reduce hypersensitivity of the teeth,     -   iv. reduce or inhibit gingivitis,     -   v. promote healing of sores or cuts in the mouth,     -   vi. reduce levels of acid producing bacteria,     -   vii. to increase relative levels of arginolytic bacteria,     -   viii. inhibit microbial bio film formation in the oral cavity,     -   ix. raise and/or maintain plaque pH at levels of at least pH 5.5         following sugar challenge,     -   x. reduce plaque accumulation,     -   xi. treat dry mouth,     -   xii. enhance systemic health, including cardiovascular health.         e.g., by reducing potential for systemic infection via the oral         tissues,     -   xiii. Whiten teeth,     -   xiv. reduce erosion of the teeth,     -   xv. immunize (or protect) the teeth against cariogenic bacteria         and their effects, and/or     -   xvi. clean the teeth and oral cavity.

The invention further comprises the use of sodium bicarbonate, sodium methyl cocoyl taurate (tauranol), methylisothiazolinone, and benzyl alcohol and combinations thereof in the manufacture of a Composition of the Invention, e.g., for use in any of the indications set forth in the above method of Composition 1.0, et seq.

DETAILED DESCRIPTION

As used herein, the term “oral composition” means the total composition that is delivered to the oral surfaces. The composition is further defined as a product which, during the normal course of usage, is not, the purposes of systemic administration of particular therapeutic agents, intentionally swallowed but is rather retained in the oral cavity for a time sufficient to contact substantially all of the dental surfaces and/or oral tissues for the purposes of oral activity. Examples of such compositions include, but are not limited to, toothpaste or a dentifrice, a mouthwash or a mouth rinse, a topical oral gel, a denture cleanser, and the like.

As used herein, the term “dentifrice” means paste, gel, or liquid formulations unless otherwise specified. The dentifrice composition can be in any desired form such as deep striped, surface striped, multi-layered, having the gel surrounding the paste, or any combination thereof. Alternatively the oral composition is provided as a dual phase composition, wherein individual compositions are combined when dispensed from a separated compartment dispenser.

Basic Amino Acids

The basic amino acids which can be used in the compositions and methods of the invention include not only naturally occurring basic amino acids, such as arginine, lysine, and histidine, but also any basic amino acids having a carboxyl group and an amino group in the molecule, which are water-soluble and provide an aqueous solution with a pH of 7 or greater.

Accordingly, basic amino acids include, but are not limited to, arginine, lysine, serine, citrullene, ornithine, creatine, histidine, diaminobutanoic acid, diaminoproprionic acid, salts thereof or combinations thereof. In a particular embodiment, the basic amino acids are selected from arginine, citrullene, and ornithine.

In certain embodiments, the basic amino acid is arginine, for example, L-arginine, or a salt thereof.

The compositions of the invention are intended for topical use in the mouth and so salts for use in the present invention should be safe for such use, in the amounts and concentrations provided. Suitable salts include salts known in the art to be pharmaceutically acceptable salts which are generally considered to be physiologically acceptable in the amounts and concentrations provided. Physiologically acceptable salts include those derived from pharmaceutically acceptable inorganic or organic acids or bases, for example acid addition salts formed by acids which form a physiological acceptable anion, e.g., hydrochloride or bromide salt, and base addition salts formed by bases which form a physiologically acceptable cation, for example those derived from alkali metals such as potassium and sodium or alkaline earth metals such as calcium and magnesium. Physiologically acceptable salts may be obtained using standard procedures known in the art, for example, by reacting a sufficiently basic compound such as an amine with a suitable acid affording a physiologically acceptable anion.

Fluoride Ion Source

The oral care compositions may further include one or more fluoride ion sources, e.g., soluble fluoride salts. A wide variety of fluoride ion-yielding materials can be employed as sources of soluble fluoride in the present compositions. Examples of suitable fluoride ion-yielding materials are found in U.S. Pat. No. 3,535,421, to Briner et al.; U.S. Pat. No. 4,885,155, to Parran, Jr. et al. and U.S. Pat. No. 3,678,154, to Widder et al., each of which are incorporated herein by reference. Representative fluoride ion sources used with the present invention (e.g., Composition 1.0 et seq.) include, but are not limited to, stannous fluoride, sodium fluoride, potassium fluoride, sodium monofluorophosphate, sodium fluorosilicate, ammonium fluorosilicate, amine fluoride, ammonium fluoride, and combinations thereof. In certain embodiments the fluoride ion source includes stannous fluoride, sodium fluoride, sodium monofluorophosphate as well as mixtures thereof. Where the formulation comprises calcium salts, the fluoride salts are preferably salts wherein the fluoride is covalently bound to another atom, e.g., as in sodium monofluorophosphate, rather than merely ionically bound, e.g., as in sodium fluoride.

Surfactants

The invention may in some embodiments contain anionic surfactants, e.g., the Compositions of Composition 1.0, et seq., for example, water-soluble salts of higher fatty acid monoglyceride monosulfates, such as the sodium salt of the monosulfated monoglyceride of hydrogenated coconut oil fatty acids such as sodium N-methyl N-cocoyl taurate, sodium coco-glyceride sulfate; higher alkyl sulfates, such as sodium lauryl sulfate; higher alkyl-ether sulfates, e.g., of formula CH₃(CH₂)_(m)CH₂(OCH₂CH₂)_(n)OS0₃X, wherein m is 6-16, e.g., 10, n is 1-6, e.g., 2, 3 or 4, and X is Na or, for example sodium laureth-2 sulfate (CH₃(CH2)₁₀CH₂(OCH₂CH₂)₂OSO₃Na); higher alkyl aryl sulfonates such as sodium dodecyl benzene sulfonate (sodium lauryl benzene sulfonate); higher alkyl sulfoacetates, such as sodium lauryl sulfoacetate (dodecyl sodium sulfoacetate), higher fatty acid esters of 1,2 dihydroxy propane sulfonate, sulfocolaurate (N-2-ethyl laurate potassium sulfoacetamide) and sodium lauryl sarcosinate. By “higher alkyl” is meant, e.g., C₆₋₃₀ alkyl. In particular embodiments, the anionic surfactant (where present) is selected from sodium lauryl sulfate and sodium ether lauryl sulfate. When present, the anionic surfactant is present in an amount which is effective, e.g., >0.001% by weight of the formulation, but not at a concentration which would be irritating to the oral tissue, e.g., 1%, and optimal concentrations depend on the particular formulation and the particular surfactant. In one embodiment, the anionic surfactant is present at from 0.03% to 5% by weight, e.g., 1.5%.

Cationic surfactants useful in the present invention can be broadly defined as derivatives of aliphatic quaternary ammonium compounds having one long alkyl chain containing 8 to 18 carbon atoms such as lauryl trimethylammonium chloride, cetyl pyridinium chloride, cetyl trimethylammonium bromide, di-isobutylphenoxyethyldimethylbenzylammonium chloride, coconut alkyltrimethylammonium nitrite, cetyl pyridinium fluoride, and mixtures thereof. Illustrative cationic surfactants are the quaternary ammonium fluorides described in U.S. Pat. No. 3,535,421, to Briner et al., herein incorporated by reference. Certain cationic surfactants can also act as germicides in the compositions.

Illustrative nonionic surfactants of Composition 1.0, et seq., that can be used in the compositions of the invention can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound which may be aliphatic or alkylaromatic in nature. Examples of suitable nonionic surfactants include, but are not limited to, the Pluronics, polyethylene oxide condensates of alkyl phenols, products derived from the condensation of ethylene oxide with the reaction product of propylene oxide and ethylene diamine, ethylene oxide condensates of aliphatic alcohols, long chain tertiary amine oxides, long chain tertiary phosphine oxides, long chain dialkyl sulfoxides and mixtures of such materials. In a particular embodiment, the composition of the invention comprises a nonionic surfactant selected from polaxamers (e.g., polaxamer 407), polysorbates (e.g., polysorbate 20), polyoxyl hydrogenated castor oils (e.g., polyoxyl 40 hydrogenated castor oil), and mixtures thereof.

Illustrative amphoteric surfactants of Composition 1.0, et seq., that can be used in the compositions of the invention include betaines (such as cocamidopropylbetaine), derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be a straight or branched chain and wherein one of the aliphatic substituents contains about 8-18 carbon atoms and one contains an anionic water-solubilizing group (such as carboxylate, sulfonate, sulfate, phosphate or phosphonate), and mixtures of such materials.

Illustrative zwitterionic surfactants of Composition 1.0, et seq., that can be used in the compositions of the invention include derivatives of aliphatic quaternary ammonium, phosphonium and sulfonium compounds in which the aliphatic radical can be a straight or branched chain and wherein one of the aliphatic substituents contains about 8-18 carbon atoms and one contains an anionic water-solubilizing group (such as carboxy, sulfonate, sulfate, phosphate or phosphonate). The surfactant or mixtures of compatible surfactants can be present in the compositions of the present invention in 0.1% to 5%, in another embodiment 0.3% to 3% and in another embodiment 0.5% to 2% by weight of the total composition.

Flavoring Agents

The oral care compositions of the invention may also include a flavoring agent. Flavoring agents which are used in the practice of the present invention include, but are not limited to, essential oils and various flavoring aldehydes, esters, alcohols, and similar materials, as well as sweeteners such as sodium saccharin. Examples of the essential oils include oils of spearmint, peppermint, wintergreen, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, lemon, lime, grapefruit, and orange. Also useful are such chemicals as menthol, carvone, and anethole. Certain embodiments employ the oils of peppermint and spearmint.

The flavoring agent is incorporated in the oral composition at a concentration of 0.01 to 1% by weight.

Chelating and Anti-Calculus Agents

The oral care compositions of the invention (e.g., Composition 1.0 et seq) also may include one or more chelating agents able to complex calcium found in the cell walls of the bacteria. Binding of this calcium weakens the bacterial cell wall and augments bacterial lysis.

Another group of agents suitable for use as chelating or anti-calculus agents in the present invention are the soluble pyrophosphates. The pyrophosphate salts used in the present compositions can be any of the alkali metal pyrophosphate salts. In certain embodiments, salts include tetra alkali metal pyrophosphate, dialkali metal diacid pyrophosphate, trialkali metal monoacid pyrophosphate and mixtures thereof, wherein the alkali metals are sodium or potassium. The salts are useful in both their hydrated and unhydrated forms. An effective amount of pyrophosphate salt useful in the present composition is generally enough to provide least 0.1 wt. % pyrophosphate ions, e.g., 0.1 to 3 wt 5, e.g., 0.1 to 2 wt %, e.g., 0.1 to 1 wto %, e.g., 0.2 to 0.5 wt %. The pyrophosphates also contribute to preservation of the compositions by lowering the effect of water activity.

Polymers

The oral care compositions of the invention (e.g., Composition 1.0, et seq) also optionally include one or more polymers, such as polyethylene glycols, polyvinyl methyl ether maleic acid copolymers, polysaccharides (e.g., cellulose derivatives, for example carboxymethyl cellulose, or polysaccharide gums, for example xanthan gum or carrageenan gum). Acidic polymers, for example polyacrylate gels, may be provided in the form of their free acids or partially or fully neutralized water soluble alkali metal (e.g., potassium and sodium) or ammonium salts. Certain embodiments include 1:4 to 4:1 copolymers of maleic anhydride or acid with another polymerizable ethylenically unsaturated monomer, for example, methyl vinyl ether (methoxyethylene) having a molecular weight (M.W.) of about 30,000 to about 1,000,000. These copolymers are available for example as Gantrez AN 139 (M.W. 500,000), AN 1 19 (M.W. 250,000) and S-97 Pharmaceutical Grade (M.W. 70,000), of GAF Chemicals Corporation.

Other operative polymers include those such as the 1:1 copolymers of maleic anhydride with ethyl acrylate, hydroxyethyl methacrylate, N-vinyl-2-pyrollidone, or ethylene, the latter being available for example as Monsanto EMA No. 1 103, M.W. 10,000 and EMA Grade 61, and 1:1 copolymers of acrylic acid with methyl or hydroxyethyl methacrylate, methyl or ethyl acrylate, isobutyl vinyl ether or N-vinyl-2-pyrrolidone.

Suitable generally, are polymerized olefinically or ethylenically unsaturated carboxylic acids containing an activated carbon-to-carbon olefinic double bond and at least one carboxyl group, that is, an acid containing an olefinic double bond which readily functions in polymerization because of its presence in the monomer molecule either in the alpha-beta position with respect to a carboxyl group or as part of a terminal methylene grouping. Illustrative of such acids are acrylic, methacrylic, ethacrylic, alpha-chloroacrylic, crotonic, beta-acryloxy propionic, sorbic, alpha-chlorosorbic, cinnamic, beta-styrylacrylic, muconic, itaconic, citraconic, mesaconic, glutaconic, aconitic, alpha-phenylacrylic, 2-benzyl acrylic, 2-cyclohexylacrylic, angelic, umbellic, fumaric, maleic acids and anhydrides. Other different olefinic monomers copolymerizable with such carboxylic monomers include vinylacetate, vinyl chloride, dimethyl maleate and the like. Copolymers contain sufficient carboxylic salt groups for water-solubility.

A further class of polymeric agents includes a composition containing homopolymers of substituted acrylamides and/or homopolymers of unsaturated sulfonic acids and salts thereof, in particular where polymers are based on unsaturated sulfonic acids selected from acrylamidoalykane sulfonic acids such as 2-acrylamide 2 methylpropane sulfonic acid having a molecular weight of about 1,000 to about 2,000,000, described in U.S. Pat. No. 4,842,847, Jun. 27, 1989 to Zahid, incorporated herein by reference.

Another useful class of polymeric agents includes polyamino acids, particularly those containing proportions of anionic surface-active amino acids such as aspartic acid, glutamic acid and phosphoserine, as disclosed in U.S. Pat. No. 4,866,161 Sikes et al., incorporated herein by reference.

In preparing oral care compositions, it is sometimes necessary to add some thickening material to provide a desirable consistency or to stabilize or enhance the performance of the formulation. In certain embodiments, the thickening agents are carboxyvinyl polymers, carrageenan, xanthan gum, hydroxyethyl cellulose and water soluble salts of cellulose ethers such as sodium carboxymethyl cellulose and sodium carboxymethyl hydroxyethyl cellulose. Natural gums such as karaya, gum arabic, and gum tragacanth can also be incorporated. Colloidal magnesium aluminum silicate or finely divided silica can be used as component of the thickening composition to further improve the composition's texture. In certain embodiments, thickening agents in an amount of about 0.5% to about 5.0% by weight of the total composition are used.

Abrasives

Generally, the inclusion of abrasives in dentifrice formulations is necessary for effective cleaning of teeth by brushing. It has been determined that by including an abrasive silica having an acid pH in the composition, compositions of enhanced viscosity stability are obtained. Prophy silica available from Grace, offered as Sylodent™, can be used with various embodiments of the present invention (e.g., Composition 1.0 et seq).

The acidic silica abrasive is included in the dentifrice components at a concentration of about 2 to about 35% by weight; about 3 to about 20% by weight, about 3 to about 15% by weight, about 10 to about 15% by weight. For example, the acidic silica abrasive may be present in an amount selected from 2 wt. %, 3 wt. %, 4% wt. %, 5 wt. %, 6 wt. %, 7 wt. %, 8 wt. %, 9 wt. %, 10 wt. %, 11 wt. %, 12 wt. %, 13 wt. %, 14 wt. %, 15 wt. %, 16 wt. %, 17 wt. %, 18 wt. %, 19 wt. %, 20 wt. %.

A commercially available acidic silica abrasive is Sylodent 783 available from W. R. Grace & Company, Baltimore, Md. Sylodent 783 has a pH of 3.4-4.2 when measured as a 5% by weight slurry in water. For use in the present invention, the silica material has an average particle size of less than 10 microns, e.g., 3-7 microns, e.g. about 5.5 microns. For example a small particle silica may have an average particle size (D50) of 2.5-4.5 microns.

The composition may also include any silica suitable for oral care compositions, such as precipitated silicas or silica gels. For example synthetic amorphous silica. Silica may also be available as a thickening agent, e.g., particle silica. For example, the silica can also be small particle silica (e.g., Sorbosil AC43 from PQ Corporation, Warrington, United Kingdom). However the additional abrasives are preferably not present in a type or amount so as to increase the RDA of the dentifrice to levels which could damage sensitive teeth, e.g., greater than 130.

The invention may also comprise a commercially available cleaning silica in certain embodiments of the invention (e.g., any of Composition 1.0, el seq). Zeodent 114 offered by J. M. Huber Finland Oy Telakkatie 5 FIN-49460 Hamina, is one such commercially available silica.

Water

Water is present in the oral compositions of the invention. Water, employed in the preparation of commercial oral compositions should be deionized and free of organic impurities. Water commonly makes up the balance of the compositions and includes 5% to 45%, e.g., 10% to 20%, e.g., 25-35%, by weight of the oral compositions. This amount of water includes the free water which is added plus that amount which is introduced with other materials such as with sorbitol or silica or any components of the invention. The Karl Fischer method is a one measure of calculating free water.

Humectants

Within certain embodiments of the oral compositions (e.g., Composition 1.0 et seq), it is also desirable to incorporate a humectant to reduce evaporation and also contribute towards preservation by lowering water activity. Certain humectants can also impart desirable sweetness or flavor to the compositions. The humectant, on a pure humectant basis, generally includes 15% to 70% in one embodiment or 30% to 65% in another embodiment by weight of the composition.

Suitable humectants include edible polyhydric alcohols such as glycerin, sorbitol, xylitol, propylene glycol as well as other polyols and mixtures of these humectants. Mixtures of glycerin and sorbitol may be used in certain embodiments as the humectant component of the compositions herein.

The present invention in its method aspect involves applying to the oral cavity a safe and effective amount of the compositions described herein.

The compositions and methods according to the invention (e.g., Composition 1.0 et seq) can be incorporated into oral compositions for the care of the mouth and teeth such as toothpastes, transparent pastes, gels, mouth rinses, sprays and chewing gum.

In some embodiments, the present invention provides an oral care composition comprising: a basic amino acid in free or salt wherein the amino acid is selected from arginine, lysine, and a combination thereof; a combination of zinc ion sources; and from about 0.75 wt. % to about 2 wt. % of a chelating system. In some embodiments, the chelating system comprises a phosphate. In some embodiments, the phosphate comprises tetrasodium pyrophosphate.

Some embodiments provide compositions further comprising a thickening system comprising: from about 0.1 wt. % to about 2 wt. % of a nonionic cellulose ether; and from about 0.25 wt. % to about 1 wt. % of a polysaccharide gum.

In some embodiments, the nonionic cellulose ether comprises hydroxyethylcellulose. In further embodiments, the oral care composition comprises from about 0.5 wt. % to about 1 wt. % of hydroxyethylcellulose. Still further embodiments provide oral care compositions comprising from about 0.6 wt. % to about 0.8 wt. % of hydroxyethylcellulose. In some embodiments, the hydroxyethylcellulose has a viscosity, measured at 2% in water at 25° C., of from about 4500 to 6500 cps. In some embodiments, the hydroxyethylcellulose having a viscosity, measured at 2% in water at 25° C., of from about 4500 to 6500 cps is present in the amount of from about 0.1 wt. % to about 0.3 wt. %, of the oral care composition. In some embodiments, the hydroxyethylcellulose having a viscosity, measured at 2% in water at 25° C., of from about 150 to 450 cps, is present in the amount of from about 0.5 wt. % to about 1 wt. %.

In some embodiments, the polysaccharide gum is xanthan gum. In some embodiments, the oral care composition comprises from about 0.3 wt. % to about 0.8 wt. % of xanthan gum.

In some embodiments, the oral care composition comprises about 1.0 wt. % zinc oxide; about 0.5 wt. % zinc citrate; about 1.5 wt. % L-arginine; from about 0.75 wt. % to about 2 wt. % of tetrasodium pyrophosphate.

In further embodiments, the oral care composition loses less than about 45% of its initial viscosity after 13 weeks. In some embodiments, the oral care composition loses less than about 40% of its initial viscosity after 13 weeks. In other embodiments, the oral care composition loses less than about 35% of its initial viscosity after 13 weeks. In yet other embodiments, the oral care composition loses less than about 30% of its initial viscosity after 13 weeks. In some embodiments, the oral care composition loses less than about 25%, 20%, 15%, 10%, 5% or 3% of its initial viscosity after 13 weeks.

In some embodiments, the oral care composition has a G′/G″ ratio of greater than 0.5. In some embodiments, the oral care composition has a G′/G″ ratio of greater than 0.75. In some embodiments, the oral care composition has a G′/G″ ratio of greater than 1. In some embodiments, the oral care composition has a G′/G″ ratio of greater than 1.5. In some embodiments, the oral care composition has a G′/G″ ratio of less than 2. In some embodiments, the oral care composition has a G′/G″ ratio of less than 1.5. In some embodiments, the oral care composition has a G′/G″ ratio of less than 1.

In some embodiments, the oral care composition has a G′/G″ ratio of between about 0.5 and about 2. In some embodiments, the oral care composition has a G′/G″ ratio of between about 0.5 and about 1.5. In some embodiments, the oral care composition has a G′/G″ ratio of between about 0.5 and about 1. Methods of quantifying the elastic modulus (G′), the loss modulus (G″) and G′/G″ ratios are described, for example, in WO 2013/089734 A1, the contents of which are hereby incorporated herein by reference in their entirety.

As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by reference in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls. It is understood that when formulations are described, they may be described in terms of their ingredients, as is common in the art, notwithstanding that these ingredients may react with one another in the actual formulation as it is made, stored and used, and such products are intended to be covered by the formulations described.

The following examples further describe and demonstrate illustrative embodiments within the scope of the present invention. The examples are given solely for illustration and are not to be construed as limitations of this invention as many variations are possible without departing from the spirit and scope thereof.

EXAMPLES Example 1

The examples herein detail how the viscosity over time for a composition which exhibits a problem of rapid reduction in viscosity (Run A), is compared to five compositions which show the stabilized viscosity provided by the invention (Compositions 1-5 in Table 1).

Viscosity is measured on a Brookfield HADV2 viscometer using a V74 vane spindle. This viscometer applies a user-controlled angular velocity to the spindle, typically measured in rotations per second (RPM), and reports torque on the shaft of the spindle. Viscosity is then calculated from RPM and torque as explained in the Brookfield Manual (Operating Instructions) using too conversion parameters SRC (shear rate constant) and SMC (spindle multiplier constant). The conversion parameters are defined as follows: SMC=290, SRC=0.2723. The test is performed at room temperature, and varies between 22 and 25 deg. C. During the test, RPM of the spindle is swept from 200 to 0.5 in 12 steps, 10 seconds per step. The viscosity reading reported is taken at RPM=1.

Compositions containing zinc oxide, zinc citrate, arginine and a fluoride source are prepared as described in Table 1, below. All compositions are formulated to provide a 10% pH of 8-8.5 using 0-0.35% phosphoric acid. The composition identified as Run A does not contain a silica abrasive which exhibits an acid pH when measured as an aqueous slurry. The compositions identified as Compositions 1-5 in Table 1 (below) contain a silica abrasive which exhibits an acid pH (Prophy Silica—Sylodent 783) when measured as an aqueous slurry in varying amounts, as detailed below.

TABLE 1 Dentifrice Formulations Experiment ID INGREDIENTS Run A Composition 1 Composition 2 Composition 3 Composition 4 Composition 5 99.0%-101.0% 35 35 35 35 35 35 GLYCERIN - USP, EP VEG DEMINERALIZED Q.S. Q.S. Q.S. Q.S. Q.S. Q.S. WATER PROPHY 0 15 10 5 5 3 SILICA (SYLODENT 783) ABRASIVES (e.g., 20 5 10 15 15 17 includes Abrasive silcas, High Cleaning Silicas) SILICA- 6.5 7 7 7 7 7 THICKENER ANIONIC 2 2 2 2 2 2 SURFACTANT L-ARGININE 1.5 1.5 1.5 1.5 1.5 1.5 AMPHOTERIC 1.25 1.25 1.25 1.25 1.25 1.25 SURFACTANT NON-IONIC 0.75 0.75 0.75 0.75 0.75 0.75 SURFACTANT ZINC OXIDE 1 1 1 1 1 1 POLYMER 1 1.3 1.3 1.3 1.3 1.3 COLORANT 0.75 0.75 0.75 0.75 0.75 0.75 ALKALI 0.5 0.5 0.5 0.5 0.5 0.5 PHOSPHATE SALT ZINC 0.5 0.5 0.5 0.5 0.5 0.5 CITRATE TRIHYDRATE PRESERVATIVE 0.4 0.4 0.4 0.4 0.4 0.4 SODIUM 0.32 0.32 0.32 0.32 0.32 0.32 FLUORIDE - USP, EP 85% SYRUPY 0.35 0 0 0 0 0 PHOSPHORIC ACID - FOOD GRADE FLAVORING 2 2 2 2 1.82 1.52 AGENT TOTAL 100 100 100 100 100 100 COMPONENTS

The composition identified as Run A displays an initial viscosity which is initially 500,000 cps to 600,000 cps high, but decreases to under 400,000 cps in 2 weeks, and under 200,000 cps at 6 weeks. Surprisingly, the compositions containing a silica abrasive which exhibits an acid pH (Prophy Silica—Sylodent 783) when measured as an aqueous slurry, Compositions 1 to 5 in Table 1 (above), eliminate this undesirable characteristic and instead produce viscosities that are stable or increase over time (See, Table 2 below).

TABLE 2 Viscosity data Experiment ID Composition Composition Composition Composition Composition Run A 1 2 3 4 5 Time Viscosity (cps) 0 491040 363489 1 d 539119 211912 300155 272475 5 d 601597 309816 1 wk 627362 288561 383245 371651 2 wk 433485 340733 328495 403212 364565 3 wk 343310 314325 334292 4 wk 224794 395483 304019 430909 423823 5 wk 375515 338801 322698 6 wk 193233 376804 344598 334292 406432 442503 7 wk 334292 9 wk 387753 10 wk 351039 364565 11 wk 158451 373583 381956 12 wk 405788 357480 13 wk 405788 398059 393550

Upon further investigation, it was found that the silica abrasive which exhibits an acid pH when measured as an aqueous slurry silica is acidic (pH 3.4-4.2) does not require phosphoric acid to adjust the product pH. Other abrasive silicas and high cleaning silicas are about neutral in pH (pH 7-8) and thus, require phosphoric acid for pH adjustment.

TABLE 3 Compo- Compo- Compo- sition 6 sition 7 sition 8 Demineralized Water Q.S. Q.S. Q.S. Glycerin - 99.5% 35 35 35 Polymer 1.2 1.2 1.2 Zinc Oxide 1 1 1 Zinc Citrate 0.5 0.5 0.5 Alkali Phosphate Salt 0.5 0.5 0.5 Flavoring agent 1.82 1.82 1.82 Sodium Fluoride 0.32 0.32 0.32 Colorant 0.75 0.75 0.75 L-Arginine 1.5 1.5 1.5 Non-Ionic Surfactant 0.5 0.5 0.5 Abrasives (e.g., includes Abrasive 8 10 12 Silcas, High Cleaning Silicas) Prophy silica (Sylodent 783) 7 5 3 Silica - thickener 7 7 8.5 Preservative 0.4 0.4 0.4 Anionic Surfactant 5.7 5.7 5.7 Amphoteric Surfactant 1.25 1.25 1.25 Total Components 100 100 100

Upon further investigation, when phosphoric acid is removed from further formulations (Compositions 6-8 in Table 3, above), they demonstrate improvement in viscosity stability, and this viscosity trend remained relatively stable from day 1 to 4 weeks when tested at: room temperature, 40° C. and 49° C. The data is further detailed in Table 4 below.

TABLE 4 Composition 6 Composition 7 Composition 8 Viscosity, Viscosity, Viscosity, 10³ cps 10³ cps 10³ cps 40° 49° 40° 49° 40° 49° RT C. C. RT C. C. RT C. C. 0 471 324 336 0.14 370 197 268 1 363 418 390 200 227 258 230 256 263 2 360 430 440 201 243 269 220 250 258 3 325 205 246 245 228 277 274 4 314 412 385 224 253 253 227 268 272 6 327 218 233

Example 2

Table 5 (below) describes the formulas for three exemplary compositions of the present invention (Compositions 9-12) and two comparative formulas (Comparative Examples I and II).

TABLE 5 Comparative Comparative Composition 9 Composition 10 Composition 11 Composition 12 Example I Example II Ingredient Wt % GLYCERIN 35.000 35.000 35.000 35.000 35.000 35.000 WATER 31.460 31.2100 30.710 30.210 32.210 31.710 ABRASIVE SILICA 10.000 10.000 10.000 10.000 10.000 10.000 SILICA-THICKENER 6.000 6.000 6.000 6.000 6.000 6.000 AMORPHOUS SILICA 5.000 5.000 5.000 5.000 5.000 5.000 Na-LAURYL SULFATE 2.000 2.000 2.000 2.000 2.000 2.000 Flavor 1.500 1.500 1.500 1.500 1.500 1.500 L-ARGININE 1.500 1.500 1.500 1.500 1.500 1.500 COCAMIDOPROPYL 1.250 1.250 1.250 1.250 1.250 1.250 BETAINE ZINC OXIDE 1.000 1.000 1.000 1.000 1.000 1.000 TITANIUM DIOXIDE 0.750 0.750 0.750 0.750 0.750 0.750 XANTHAN GUM 0.400 0.400 0.400 0.400 0.400 0.400 SODIUM CMC 1.000 1.000 1.000 1.000 1.000 1.000 TETRASODIUM 0.750 1.000 1.500 2.000 — 0.500 PYROPHOSPHATE ZINC CITRATE 0.500 0.500 0.500 0.500 0.500 0.500 TRIHYDRATE POLOXAMER 407 0.500 0.500 0.500 0.500 0.500 0.500 BENZYL ALCOHOL 0.400 0.400 0.400 0.400 0.400 0.400 PHOSPHORIC ACID 0.350 0.350 0.350 0.350 0.350 0.350 SODIUM FLUORIDE 0.320 0.320 0.320 0.320 0.320 0.320 SODIUM SACCHARIN 0.300 0.300 0.300 0.300 0.300 0.300 SUCRALOSE 0.020 0.020 0.020 0.020 0.020 0.020

Example 3

Table 6 (below) describes the results of viscosity evaluations performed on exemplary compositions of the present invention and two reference formulas. Viscosity is measured in accordance with the methods described herein.

TABLE 6 TSPP Concentration (Wt. %) 0% 0.5% 0.75% 1% 1.5% 2% C.E. I C.E. II Comp. 9 Comp. 10 Comp. 11 Comp. 12 Time Viscosity (cP) Initial 191944 465046 459508 377273 453452 454741 4 weeks 180139 223191 — 402198 407296 402198 8 weeks 206115 242185 390585 475996 447011 441214 13 weeks  187398 237620 296872 447507 440166 436496 Viscosity 2.37 48.90 35.39 −18.62 2.93 4.01 Drop (%)

The data described in Table 6 (above) demonstrates the unexpected stabilizing effects provided by the inventive phosphate systems of the present invention.

Example 4

Table 7 (below) describes the formulas for two additional exemplary compositions of the present invention (Compositions 13 and 14).

TABLE 7 Compo- Compo- sition 13 sition 14 Ingredient Wt % GLYCERIN 35.000 35.000 SUCRALOSE 0.0200 0.0200 WATER 31.560 30.560 SODIUM SACCHARIN 0.300 0.300 ABRASIVE SILICA 10.000 10.000 SILICA-THICKENER 6.000 6.000 AMORPHOUS SILICA 5.000 5.000 Na-LAURYL SULFATE 2.000 2.000 Flavor 1.500 1.500 L-ARGININE 1.500 1.500 COCAMIDOPROPYL BETAINE 1.250 1.250 ZINC OXIDE 1.000 1.000 TITANIUM DIOXIDE 0.750 0.750 XANTHAN GUM 0.400 0.400 SODIUM CMC 1.000 1.000 HYDROXYETHYL CELLULOSE — — (HEC) TETRASODIUM PYROPHOSPHATE 1.000 2.000 ZINC CITRATE TRIHYDRATE 0.500 0.500 POLOXAMER 407 0.500 0.500 BENZYL ALCOHOL 0.400 0.400 85% PHOSPHORIC ACID — — SODIUM FLUORIDE 0.320 0.320

Example 5

Table 8 (below) describes the percentage change in viscosity loss for two exemplary compositions of the present invention (Compositions 13 and 14). Viscosity is measure in accordance with the methods described hereinabove.

TABLE 8 TSPP Concentration (Wt. %) 1% 2% Comp. 13 Comp. 14 Time Viscosity (cP) Initial 271170 346530 4 weeks 260808 329469 8 weeks 278258 332557 13 weeks  272402 338936 Viscosity −0.45 2.19 Drop (%)

The data described in Table 8 (above) shows that compositions of the present invention demonstrate minimal viscosity loss over extended periods of time.

As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.

Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight. The amounts given are based on the active weight of the material.

While the present invention has been described with reference to embodiments, it will be understood by those skilled in the art that various modifications and variations may be made therein without departing from the scope of the present invention as defined by the appended claims. 

What is claimed is:
 1. An oral care composition comprising: a. a basic amino acid in free or salt form wherein the amino acid is arginine; b. a combination of zinc ion sources, wherein the zinc ion sources comprise zinc oxide and zinc citrate, and wherein the weight ratio of zinc oxide to zinc citrate is about 2:1; c. from about 1% wt % to about 2 wt. % of a chelating system, wherein the chelating system comprises tetrasodium pyrophosphate; d. a thickening system comprising one or more selected from the group consisting of xanthan gum, finely divided silica; wherein the oral care composition loses less than about 5% of its initial viscosity after 13 weeks.
 2. The oral care composition of claim 1, comprising, about 1% wt. %, about 1.25 wt. %, about 1.25 wt. %, about 1.5 wt. %, about 1.75 wt. %, or about 2 wt. % of the chelating system.
 3. The oral care composition according to claim 1, wherein the xanthan gum is present in an amount of from about 0.3 wt. % to about 0.8 wt. % of the total weight of the oral care composition.
 4. The oral care composition according to claim 1, wherein the thickening system further comprises from about 5 wt. % to about 10 wt. % silica.
 5. The oral care composition according to claim 1, wherein the thickening system comprises from about 0.5 wt. % to about 15 wt. % of the oral care composition.
 6. The oral care composition according to claim 1, wherein the amino acid is arginine, and is present at about 1.5 wt. %, 5 wt. %, or about 8 wt. %, of the oral care composition.
 7. The oral care composition according to claim 1, wherein the zinc citrate is in an amount of about 0.5 wt. % and zinc oxide is present in an amount of about 1.0 wt. % based on the total weight of the oral care composition.
 8. The oral care composition according to claim 1, further comprising a fluoride ion source selected from sodium fluoride, sodium monofluorophosphate, and stannous fluoride.
 9. The oral care composition according to claim 8, wherein the fluoride ion source is present in an amount of from about 0.1 wt. % to 2 wt. % of the total weight of the oral care composition.
 10. The oral care composition according to claim 8, wherein the fluoride ion source provides soluble fluoride in amount of 50 to 25,000 ppm fluoride.
 11. The oral care composition according to claim 8, wherein the fluoride ion source provides soluble fluoride in an amount of about 1450 ppm.
 12. The oral care composition according to claim 8, wherein the fluoride ion source is sodium fluoride, is present in an amount of about 0.32 wt. %.
 13. The oral care composition according to claim 8, wherein the fluoride ion source is stannous fluoride.
 14. The oral care composition according to claim 8, comprising: a. about 1.0 wt. % zinc oxide; b. about 0.5 wt. % zinc citrate; c. about 1.5 wt. % L-arginine; and d. from about 1 wt. % to about 2 wt. % of tetrasodium pyrophosphate.
 15. The oral care composition according to claim 14, further comprising from about 0.3 wt. % to about 0.6 wt. % of xanthan gum.
 16. The oral care composition according to claim 1 in a form selected from: a toothpaste, a mouthwash, and an oral gel.
 17. The oral care composition according to claim 1, having a G′/G″ ratio of greater than 1 and less than
 2. 18. A method to improve oral health comprising applying an effective amount of the oral care composition according to claim 1 to the oral cavity of a subject in need thereof, wherein the method is effective to: i. reduce or inhibit formation of dental caries, ii. reduce, repair or inhibit early enamel lesions, e.g., as detected by quantitative light-induced fluorescence (QLF) or electrical caries measurement (ECM), iii. reduce or inhibit demineralization and promote remineralization of the teeth, iv. reduce hypersensitivity of the teeth, v. reduce or inhibit gingivitis, vi. promote healing of sores or cuts in the mouth, vii. reduce levels of acid producing bacteria, viii. to increase relative levels of arginolytic bacteria, ix. inhibit microbial bio film formation in the oral cavity, x. raise and/or maintain plaque pH at levels of at least pH 5.5 following sugar challenge, xi. reduce plaque accumulation, xii. treat dry mouth, xiii. enhance systemic health, including cardiovascular health, xiv. whiten teeth, xv. reduce erosion of the teeth, xvi. immunize (or protect) the teeth against cariogenic bacteria and their effects, and/or xvii. clean the teeth and oral cavity. 